The Pear Tree Psylla. 23Y 



to arise from between the front legs. The favorite feeding places 

 of the nymph, and to which their much flattened bodies are 

 well adapted, are in the axils of the leaf petioles and stems of 

 the forpiing fruit. A few nymphs emerged in the spring before 

 the leaves had expanded; these nymphs crawled into the buds out 

 of sight. "WTien the axils of the fruit stems and leaves become 

 full, the nymphs gather in closely packed clusters about the base 

 of the petioles and stems; if very numerous they gather on the 

 under sides of the leaves along the mid-rib and often on the 

 petioles of the leaf. The nymphs move about but very little, 

 sometimes becoming covered with their own honey-dew; if dis- 

 turbed they crawl about quite rapidly. The only times when the 

 nymphs seem to stop feeding is during the casting off of their 

 old skin which has become too small, and which gives place to 

 a new and elastic skin formed just beneath the old one. At 

 the last moulting of the skin, which occurs about one month after 

 the nymph's emergence from the e^g, the adult insect appears. 



Habits of the adult. — The adult insect has quite diif erent habits 

 from what it had when a nymph. The strong legs and wings 

 of the adult enable it to spring up and fly away with surprising 

 quickness upon the slightest unnatural jar or the near approach 

 of the hand to its resting place. The hibernating forms, how- 

 ever, are quite sluggish in their movements and are readily 

 captured when found. The summer forms fly readily from tree to 

 tree and could easily be borne by winds for long distances, and 

 thus infect neighboring orchards. The adults are provided with 

 a beak with which they feed upon the tissues of the leaves and 

 tender twigs of the tree. They seem to have no favorite feeding 

 place. 



Oviposition of summer broods. — Three or four days after th«'ir 

 transformation from the nymph stage, the adults of the spring 

 and summer broods copulate and egg-laying begins for another 

 brood. These eggs are usually laid singly, sometimes several in 

 a row or group, not on the twigs, but on the under side of the 

 tenderest leaves among the hairs near the mid-rib, or on the 

 petiole near the leaf; sometimes the female very adroitly plac/es 

 an egg or two in each notch of the toothed edge of the leaf. 



